Process of electrolytic production of copper.



N. V. HYBINBTTE.

PROGESS OP ELEGTROLYTIC PRODUCTION 0F COPPER.

` APPLICATION FILED MAR. 29, 1913. 1,084,150, Patented Jan. 13, 1914.

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N`OAK` VICTOR HYBINETTE, or OHRISTIANIA, NORWAY.

PROCESS or ELEOTEOLYTIC PRODUCTION or COPPER.

Toall who/m it may concern.'

Be it known that I, NOAK VICTOR HY- iNE'rrmaa subject of the King of Norway, ,residing-at Christiania, y vented certain new and useful Improvelments in Processes o f Electrolytic Production fof Copper; and I do hereby declarethe following to. be a full, clear, and exact description of the invention, such as will enable othersskilled inthe art to which it appertains to make and use the same.

In processes where copper is produced direct from ores' by leaching and electrolysisthereis generally present in the electrolyte large quantities of iron, which make the. electrolytic deposition of the copper impossible.v The trouble shows itself by dissolving the deposited copper at the top of -the cathode plate while some deposition is going on at the bottom part of the same cathode. The cathode plate is finally entirely dissolved or eaten away at the upper part, and the remainder falls to the bottom of the tank. Theoretically this is explained b lthe `fact' that the ferrie sulfatedn the electrolyte acts upon the copper at the cathode to form ferrous sulfate which is oxidized at the anode to the ferrie form and again passes to the cathode to dissolve more copper.

In' processesy heretofore used it is specilied that the presence of ferrie compounds at the cathode should be avoided, and this has -been accomplished by reducing the solution with ore to suoli an extent, as1 the nature of the ore permits, and then completing the reduction with sulfuric acid gas before passing the solution to the cathode. In connecwhich the plating has taken place forv the same reason has been constructed with a very tight diaphragm so as to prevent the ferrie salts formed at the anode from entering the cathode compartment. The above practice resulted in the production of sulfuric acid from the SO2,

and the too strongly acid solution dissolved.

undue' proportions of iron and other impurities, which made it necessary to frequently renew the electrolyte.

The object of my invention is a process worked out on the basis of a new principle or theory, whereby the process may be carried out in a more advantageous manner.

`When copper is electrolytically deposited from a solution containing copper and iron salts with the aid of an insoluble anode, thel Speciication of Letters Patent.

Application filed March 29, 1913. Serial No. 757,583.

Patented Jan. 13,1914;

` iron salts are oxidized at the anode. This oxidizing not only causes the formation of ferrie salts, but also higher oxidation com-4 pounds of iron, which, however, are decomposed by the ferrous salts present in excess of thev electrolysis. supposing now that these higher oxidized the formula FezO, the composition pf thslution at the anode may be indicatedby the formula:

The first and the last will in a short time react with the other so' as to formrFe2'O3(SO3)3, as follows If now the solution circulates in ,silcl a way that it becomes o'ssible for some of'v the solution at the ano e to reach the cathode before suiicient ltime has elapsed to allowl the higher compounds to be reduced by the ferrous salts presentin excess in the elec# trolyte, tlien metallic co'pper is dissolved,-

compounds have y of these compounds` and this explains the fact that the same cathode can be dissolved at its upper portion 'f and -have copper deposited simultaneously on its bottom portion. d

The main feature of my process consists' therefore, in that the cathode is 'separated froln the anode by a very porous diaphragm or filter, and in causing the solution cominor from the leaching tanks and containing considerable quantities of the cell at the cathode, and thereupon be allowed to li'lter through said diapliragin into the anode compartment. method the ferrie salts in the anode coinpartment are prevented from returning to the cathodes. In this Way it is possible ,to avoid the reduction of the cathode solution by the necessity of sulfuro'us acid, well as the drawbacks resulting from such reduction, and at the same time it is possible to Obtain better results in' th'e way of more complete extraction when a higher percentage of fe'rric salts is present in the solution.

According to my experiencethe process may be carried out with a solution going to the cathode cell containing, per liter, 20-80 grams of iron in the form of ferrie salts (FezOa). lVhen ferrie salts are present ferrie salts to enter at the cathode there 'is `a reduction of the. amount of copper deposited, "but thisy rel l duction is not so great as to make the process uneconomical, and as the deposition 'takes place evenly all over the surface of the cathode, there is no practical hindrance in carrying out the process. The reduction of ferrie salts to' ferrous salts, which it is nccessar to accomplish before the copper will be eposited upon the cathode is, therefore, in my process effected by the electric current, and a certain amount of electric energy is consumed for the purpose, but only so much reduction is effected as is necessar and I avoid the complete reduction an thje introduction of sulfuric acid, which has proven itself so harmful in other procees.

It has heretofore been sup osed, that no copper will be deposited be ore all fernic sa ts are reduced, but I have found that 10 to 15 grams of iron can easily be resent in the ferrie state without materia ly af fecting the eiciency as regards the amount 4of copper plated, provided,v however that care is taken, that fresh solution from the anode is not allowed to pass to the cathode.

I have constructed a diaphra especially adapted-for this process, w ich dia` phragm consists `of a very porous material -suchas loose cotton or asbestos held inplace or strengthened vby"means of a metallic (leaden) skeleton. ,This diaphragm is the subject matter of my lPatent No. 1,052,256 dated February 14, 1913. B the use of a filte partition, instead o a diaphragm in -the sual meaning of the word, I have;

less resistance, and therefore also lesspower consumption. The disadvantage of having a mechanically weak dia hragm has been material of the diap overcome by the use of t e said lead construction, which su ports the soft fibrous The accompanying drawin shows a vertical section through an efectrolytic 4cell consisting of a tank A in which the anodes B are suspended on each side of the cathode chamber uilt up of a framework K and filtering partitions D, between which is placed the cathode C. The solution enters at H, passes through the partitions D and out at G. It is evident that.not the whole of the solution need circulate through the filter or diaphragm, and that I may supply only enough solution into the cathode comepleeol this )etant my be obtained tor nv'e cents each, by addressing the Washington, D. G.

ing circulated in the anode compartment only, for the purpose of oxidizing the iron prior to leaching fresh quantities of ore. By such circulation, I am able to obtain a better oxidizing eliciency at the anode than if the circulations were limited to the small amount filtering through the diaphragms. By means of this process poor copper ores with a. large content of iron may also with advantage be treated electrolytically. OW- ing to the fact that no sulfurous acid is used, the solution can be maintained at a comparatively low degree of acidity, and this makes it possible to carry out the leaching operation with solutions after being depleted of copper' without dissolving too Vlarge quantitiesofjiron. A solution such as that employed in this'process has also the advantage of having a great dissolving power, not only upon copper compounds that are soluble in sulfuric acid, but also u on copper in other forms, such as sulfi of copper and metallic cop er.

'Ihe employment4 of a fi ter-like diaphragm 'constructed as above described facilitates the working of the process, as the diaphragm may be easily cleansed, and also easily and in an inexpensive manner renewed. 'I he` employment of leaden structures has prov'ed to be connected with no drawbacks. The utilization of this property of lead is one of the important features of this invention.

I claim f The rocess of electrolytic production of 'copper y leaching? of ore and plating from a solution containing both copper land' iron salts, which comprises passing an electrolyte containing large uantities of ferric.

salts into the cathode compartment of an RUTH Lrnns'ram.

Commissioner of Patents. 

